Hydraulic jack



(No Model.)

F. 1. JOYCE. HYDRAULIC JACK.

No. 407,217. Patented July" 16, 1889.

er, wamington. D

UNITED STATES PATENT OEEICE.

FRANK l. JOYCE, OF DAYTON, OlllO.

HYDRAULIC JACK.

SPECIFICATION forming part of Letters Patent No. 407,21*?, dated July 16, 1889.

Application tiled August 27, 1888. Serial No. 283,898. (No model.)

invention, Figure 1 is a central vertical sec-- tion of a hydraulic jack embodying my improvements. Fig. 2 is a horizontal section of the same on the line n; of Fig. 1. Fig. 3 is a central vertical section at right angles to Fig. 1, and showing the plunger in side elevation and the outlet-valve of the ram closed. Fig. .if is an enlarged sectional elevation of the lower end of the plunger and its packing, showing the inlet-valve closed.

The numeral 1 designates the frame of the jack, and 2 a hollow cylinder secured therein above and in contact with packing 3, which is placed in the bottom of the frame to pro- Vide a tight joint. \Vithin the cylinder 2 is fitted a tube 4, having a head 5 secured in its lower end and forming therewith the ram of the jack. To the upper end of the ramtube l is secured the hollow head 6, which is to support the load to be lifted or bear against the object to be moved, as the case may be.

The ram-head 5 is provided at its lower end with packing 7, which is held in place by a nut 8, as shown. 1n the center of the ram-head is a pl un ger-chamber 9, an d below this plungerchamber and communicating therewith is an outlet-valve chamber 10, in the lower end of which is secured a nut 11having openings 12 for the passage of iiuid. The nut 11 has a central guideway 13 for the stem of a valve 11, which is normally pressed upward to its seat 15 by means of a spiral spring 16, supported on the nut 11 below said valve. The upper end of the valve-stein above the valve 11 is provided with wings 17, which serve as guides for the valve-stem in the contracted passage between the valve chamber and plunger-chamber.

The plunger-rod 18 is provided at its upper end with a crank-pin 10, which is journaled in the Aforks 20 of a crank-arm 2l, that is secured to a many-sided rock-shaft 22, which is j ournalcd iu the head by means of the bosses 23, packing 24, and cylindrical jam-nuts and 26, in the manner described in my application, Serial No. 270,409, filed April 12, 1888, the object being to provide for the easy removal and replacement of the rock-shaft and plunger and at the same time prevent leakage. On one end of the rock-shaft 22 is s ecured a crank-head 27, which is perforated or recessed for the insertion of a lever to operate the plunger. The lower end of the plunger-rod is hollow or tubular and somewhat expanded to form a plunger 28, which operates in the plunger-chamber i) of the ram-head. In the plunger 28, as shown in Fig. et, is formed an inlet-valve chamber 29,into the lower end of which is screwed a nut 30, having openings 31 for the passage of fluid. This nut 30 has a central guideway 32 'for the stem of the inlet-valve 33, which is normally held up to its seat 34 by a` spiral spring 35, that is supported by the nut. On the upper end of the valve stem are wings 36, which act as guides in the hollow plunger-rod. The plunger 28 is provided with an inverted-cup packing 37, in the manner described in my hereinbefore-meutioned prior application.

In order to enable the jack to be operated equally well in either a vert-ical, horizontal, or inclined position, the hollow plunger-rod 18 is provided above and near the ram-head 5 with a lateral tube 38, which extends very nearly to the extreme side of the upper chamber 39, which contains the fluid to be cmployed for raising the ram.

lVhen the plunger 28 is lifted, it tends te arrives at the upward limit of its stroke, it will occupy the position shown in Fig. 3, and both valves and la will be closed by the As the plunger deaction of the springs.

TOO

scends, the pressure is increased in the lower part of the plunger-chamber 9, thereby causing the upper or inlet valve 33 to press more firmly on its seat and prevent the escape of4 the fluid back into the chamber 39; but at the same time this pressure causes the lower or outlet valve 14 to move away from vits seat, and the fluid thus passes through the outletvalve chamber 10 and openings 12 into the` fluid-chamber 40 beneath the ram-head 5, thereby raising the ram.

As'the tube 38, which communicates with the hollow plunger-rod, is located very near the ram-head and is of such length as to eX- tend very nearly to the extreme side of the chamber 39, it is obvious that its outer end will be submerged until nearly all the fluid in said chamber has been pumped out, even when the jack is placed in a horizontal or inclined position; and in order thatI the fluid may be compelled to flow through the tube 38 and plunger-rod 18, even after the surface of the fluid has sunk .below the central horizontal line of the plunger-chamber, the plunger is provided with the inverted-cup packing 37, which will spread and produce a per' feet vacuum in the plunger-chamber.

In order to provide for lowering the ram from a raised position, a small lby-passage 4l is formed in the ram-head 5, communicating with the plunger-chamber at both ends above and below the plunger 28 vwhen it is inthe lowest position. By forcingthe plunger down to its lowest point in the plunger-chamber, asl

shown by dotted lines in Fig. 3, the valve 14 will be pressed down away from itsseat and a passage will be afforded for the flow of fluid from the lower chamber 40, through the openings 12, valve-chamber 10, by-passage 41, and upper part of the plunger-chamber 9, to the upper chamber 39, thereby permitting the ram to descend by gravity.

What I claim as my invention is- The combination, in a hydraulic jack, of a base-frame provided with a hollow cylinder, a fluid-containing ram-tube sliding lengthwise in the cylinder, a ram-head xed to the rlower end of the ram-tube working along the cylinder and having a longitudinal chamber in communication with the fluid in the ramtube, a valve in the lower portion Vof' the ramhead, a hollow plunger-rod having ya hollow packed plunger working in the ram-head, a valve carried by and located inthe packed plunger, and a lateral tube .communicating with the hollow plungerand extending from the latterat a point above both the Vplungervalveland ram-head to a point nearly or adjacent tothe extreme side of the fluid-containing ram-tube for enabling the jack to be used in a horizontal or inclined or perpendicular position, substantially as described.v

In testimony whereof I affix my signature in presence of two witnesses.

FRANK I. JOYCE. Witnesses:

J AMES L. NoRRIs, JOS. L. COOMBS. 

